The development of scanning tunneling and atomic force microscopes has led to various kinds of applications. Examples of these applications are: scanning probe storage systems, e.g. storage systems making use of parallel local probes, scanning probe lithography systems, test equipment comprising a scanning probe or array of probes, atomic resolution, high throughput inspection systems, and scanning probe system used for the structuring of surfaces;such a semiconductor chips and the like.
Scanning probe microscopes and scanning probe storage systems making use of the tunneling current require a mechanism to ensure that the scanning probe (or arrays of scanning probes) is kept in close proximity to the sample or storage medium. This can for example be achieved by means of a special cantilever carrying a probe, as disclosed in the U.S. Pat. No. 5,036,490. Such a cantilever may be equipped with a piezoactuator, for example, to allow adjustment of the distance between storage medium and probe. To obtain a memory of sufficient storage capacity a scanning probe system (AFM- and STM-based systems) would require hundreds of cantilevers each of which being equipped with its own actuators and driving circuitry. The manufacturing of such cantilevers with piezo actuators is complicated, expensive, and the reproducibility and applicability as mass-storage devices is currently questionable.
Most atomic force scanning probe systems are operated in contact mode, i.e. the probe(s) is brought into direct contact with the sample or storage medium. To obtain information of the sample or storage medium, the probe is scanned in contact over its surface. The operation in contact mode greatly affects the reliability of the probe, which usually comprises a sharp tip-like element, due to wear-out. The wear-out in turn leads to reduced reproducibility and increased cost because the tip or probe has to be replaced from time to time. Furthermore, the surface to be scanned may be damaged.
There are other scanning probe systems where the probe, sample, or both together are oscillated. This usually leads to a situation where the tip of the probe frequently contacts the sample or storage medium. This mode of operation was, for example, addressed for the first time in the article "Atomic Force Microscope", G. Binnig and C. F. Quate, Physical Review Letters, Vol. 56, No. 9, pp. 930-933. In the following, this mode of operation is referred to as tapping mode.
As outlined above, most scanning probe systems (AFM- and STM-based) require means for adjustment/control of the distance between the scanning probe and surface to be scanned. Usually, actuators are employed requiring driving circuitry and wiring. Dense packaging is thus difficult.
Not only in case of high-end scanning probe systems, but also in case of low-end systems, there is a demand for simplification of adjustment and control of the distance between the probe on one hand and the sample or storage medium on the other hand.
Some of the above systems are also designed for use in an ultra high vacuum (UHV). The dimensions of a UHV chamber area limited and scanning probe systems of very small size are required.
It is a disadvantage of most currently available scanning probe systems that they are complex and expensive. Furthermore, the handling of such systems is usually difficult. Conventional scanning probe systems have to be operated carefully in order to avoid damage of the local probe.
It is an object of the present invention to provide simpler and more robust scanning probe systems.
It is an object of the present invention to provide a new, improved cantilever design for use in connection with, or as part of any kind of scanning probe systems, including low-end scanning probe systems.
It is a further object of the present invention to provide new or improved scanning probe systems enabled by the inventive cantilever design.